COVID-19 Is Far More Lethal, Damaging Than Flu, Data Shows

FRIDAY, Dec. 18, 2020 (HealthDay News) -- COVID-19 is far more harmful and deadly than the seasonal flu, new studies confirm.

Researchers analyzed U.S. Department of Veterans Affairs data on more than 3,600 patients hospitalized with COVID-19 between Feb. 1 and June 17 of this year, and more than 12,600 hospitalized with the flu between Jan. 1, 2017 and Dec. 31, 2019. The average age of patients in both groups was 69.

The death rate among COVID-19 patients was 18.5%, while it was 5.3% for those with the flu. Those with COVID were nearly five times more likely to die than flu patients, according to the study published online Dec. 15 in the BMJ.

COVID-19 patients with the highest risk of death included those aged 75 and older who also had chronic kidney disease or dementia, and Blacks who were obese, or who had diabetes or kidney disease.

The study also found that COVID-19 patients were four times more likely to require breathing machines, nearly 2.5 times more likely to be admitted to intensive care, and stayed in the hospital an average of three days longer than flu patients.

A separate study from France, published online Dec. 17 in The Lancet Respiratory Medicine journal, arrived at similar conclusions: Nearly twice as many people were admitted to the hospital for COVID-19 at the height of the pandemic than were for influenza at the peak of the 2018/2019 flu season. And the death rate was almost three times higher.

The French team, led by Dr. Pascale Tubert-Bitter, research director at L'Institut National de la Santé et de la Recherche Médicale (Inserm), and Catherine Quantin, from the University Hospital of Dijon and Inserm, compared data from COVID-19 patients admitted to the hospital over a two-month period in spring 2020 with influenza patients admitted over a three-month period during the seasonal flu outbreak of 2018/2019.

"The finding that the COVID-19 death rate was three times higher than for seasonal influenza is particularly striking when reminded that the 2018/2019 flu season had been the worst in the past five years in France in terms of number of deaths," Quantin noted in a Lancet news release.

Tubert-Bitter added, "Taken together, our findings clearly indicate that COVID-19 is much more serious than seasonal influenza. At a time when no treatment has been shown to be effective at preventing severe disease in COVID-19 patients, this study highlights the importance of all measures of physical prevention and underlines the importance of effective vaccines."

U.S. researchers said a big surprise in their study was that COVID-19 patients had a higher risk of developing diabetes, with 9 more cases per 100 than flu patients.

"These patients didn't have diabetes until they got COVID-19," said study senior author Dr. Ziyad Al-Aly, an assistant professor of medicine at Washington University in St. Louis. "Then their blood sugar spiked, and they needed huge doses of insulin. Is the diabetes reversible, or will it require long-term management? Will it be type 1 or type 2 diabetes? We just don't know because COVID-19 barely existed a year ago."

Another finding was that COVID-19 patients had a higher risk of acute kidney damage and severe sepsis shock. For both complications, there were an average of 6 more cases per 100 COVID-19 patients than among flu patients.

Also, COVID-19 patients were more likely to need medications to treat severely low blood pressure, a condition that can lead to organ damage and death. The rate was 11.5 more cases per 100 patients than among flu patients.

"Many high-profile, public comparisons between COVID-19 and the flu have been made; however, those comparisons mostly were drawn using disparate data and statistical methods that have resulted in a lot of conjecture. Our research represents an apples-to-apples comparison between the two diseases," Al-Aly said in a university news release.

"A deeper understanding of the health risks of COVID-19 helps to anticipate demand for health care services and to project mortality with greater accuracy," he added.

"We know so little about COVID-19 because of its newness," Al-Aly noted. "I'm not sure why Black patients suffer and die more. My hunch is that the cause relates to racial disparities in health care, but there could be other factors that we don't yet know."

More information

The U.S. Centers for Disease Control and Prevention has more on COVID-19.

SOURCES: Washington University in St. Louis, news release, Dec. 15, 2020; The Lancet Respiratory Medicine, news release, Dec. 17, 2020